#include <bits/stdc++.h>
using namespace std;
struct directedGraph{
    int N;
    vector<int> edgesValue;
    vector<vector<int>> edges;
    directedGraph(int n){
        N=n;
    }
    void addEdge(int a,int b,int value=0){
        edges.emplace_back((vector<int>){a,b});
        edgesValue.emplace_back(value);
    }
    vector<vector<int>> getConnection(){
        vector<vector<int>> ret(N,vector<int>(0));
        for(vector<int> v:edges){
            ret[v[0]].emplace_back(v[1]);
        }
        return ret;
    }
    vector<int> dijkstra(int start){
        vector<int> ret(N,-1);
        vector<vector<int>> next(N,vector<int>(0)),weight(N,vector<int>(0));
        for(int i=edges.size()-1;i>=0;--i){
        	next[edges[i][0]].emplace_back(edges[i][1]);
        	weight[edges[i][0]].emplace_back(edgesValue[i]);
        }
        auto comp=[](vector<int> a,vector<int> b){return a[1]>b[1];};
        priority_queue<vector<int>,vector<vector<int>>,decltype(comp)> que{comp};
        que.push((vector<int>){start,0});
        while(!que.empty()){
            vector<int> temp=que.top();
            if(ret[temp[0]]==-1){
                ret[temp[0]]=temp[1];
                for(int i=next[temp[0]].size()-1;i>=0;--i){
                    que.push((vector<int>){next[temp[0]][i],temp[1]+weight[temp[0]][i]});
                }
            }
            que.pop();
        }
        return ret;
    }
};

int main(){
    int N,M,K,R,A,B,C;
    cin>>N>>M>>K;
	directedGraph G(N*(1<<K));
    vector<int> mask(M,0);
    for(int i=0;i<K;++i){
        cin>>R;
        mask[R-1]=1<<i;
    }
    for(int i=0;i<M;++i){
        cin>>A>>B>>C;
        for(int j=0;j<(1<<K);++j){
            G.addEdge(A-1+j*N,B-1+(j|mask[i])*N,C);
            G.addEdge(B-1+j*N,A-1+(j|mask[i])*N,C);
        }
    }
    cout<<G.dijkstra(0)[N*(1<<K)-1]<<endl;
}